D&F Dams

What is a dam?

A structure that controls the flow of water

What are some uses of dams?

·      Create reservoirs to supress floods

·      Provide water for: irrigation, consumption, industrial use, aquaculture and navigability

·      Hydroelectric power

What is the oldest known dam?

Oldest known is the Jawa Dam in northern Jordan created between 3500-3400 BC

What kind of dams did the Romans create?

Arch-gravity, arch dams, buttress dams, multiple arch

Where is the three gorges dam?

Yangtze River in China

The three gorges damn caused

1.2 million Chinese people relocated and the world rotation to slow by .06 microseconds

Characteristics of an arch dam

A curved concrete wall that uses the force of water pressure to strengthen the structure; The arch dam is designed to straighten slightly under the force of the water, pushing into the foundation or abutments

Characteristics of a gravity dam

A dam that uses its own weight to hold back water; They are built to withstand loads by their own weight and by their resistance to sliding and overturning; Gravity dams are usually straight, but can have a curved dam axis; They have a large base and can only be built on a rock foundation. 

Characteristics of arch-gravity dams

Combines features of both arch and gravity dams, curving upstream to distribute water pressure to the canyon walls, while relying on its mass and weight for stability; Hoover Dam

Characteristics of buttress dams

A type of dam that relies on a series of supports (buttresses) on the downstream side to hold back water, with a watertight upstream side

Characteristics of barrages

Consists of a number of large gates that can be opened or closed to control the amount of water passing; A weir that has adjustable gates installed over top of it, to allow different water surface heights at different times.

Characteristics of embankment dams

Embankment dams are constructed by placing and compacting layers of earth materials in horizontal layers called lifts; Cost-effective and relatively simple to build. 

What are the two types of embankment dams?

• Earthfill dams: Filled with soil

• Rockfill dams: Filled with rocks